1. Field of the Invention
This invention relates generally to cord clamping or locking devices and more particularly, it relates to an improved cord closure formed of a plunger, a compression spring, a retaining ring, and a body housing which includes means for initially holding the plunger subassembly in a "pre-assembled" position with the spring being compressed so that the throughhole of the plunger and the holes of the body housing can be readily aligned for insertion of a cord.
2. Description of the Prior Art
Heretofore, there are known in the art various types of cord or string fasteners, which are attached to cords or drawstrings on helmets, hats, sleeping bags, hooded parkas, backpacks, garments, or any other application wherein drawstrings are employed, for releasably fastening or stopping the drawstrings. Generally, cord locks that have been developed for this purpose include telescoping cylinders having co-operating lateral apertures urged apart by a compression spring. Initially, the cylinders must be manually urged toward one another against the force of the biasing spring to align the apertures on the cylinders prior to insertion of the cord. When the force on the cylinders is released, the spring causes opposing edges of the apertures in the cylinders to clamp the cord.
Such prior art cord fasteners have the disadvantage in that a very tedious and time-consuming adjustment is necessary so as to manually align the apertures in the respective cylinders before the cord could be assembled onto the cord fastener, thereby increasing labor costs. It would therefore be desirable to provide an improved cord closure which eliminates this need of initially aligning manually the apertures in the respective cylinders. The improved cord closure also helps to avoid carpal tunnel syndrome because there is no repetitive squeezing to align the apertures when inserting a cord during assembly.
A state of the art search directed to the subject matter of this application uncovered the following U.S. Letters Patent:
______________________________________ 2,379,676 4,675,948 4,188,686 4,724,584 4,328,605 4,839,946 4,453,292 5,015,023 4,622,723 ______________________________________
There is disclosed in U.S. Pat. No. 4,328,605 to V. James Hutchison et al., issued on May 11, 1982, a cord clamp which includes a main body or sleeve 14, a piston or plunger 16, a cap 18 and a compression spring 20. The plunger 16 and the sleeve 14 are mounted together in close fitting telescopic engagement so that they are axially moveable with respect to one another. The compression spring 20 is then positioned in the sleeve 14, and the cap 18 is then placed in sealing relationship to the sleeve 14 so as to retain the spring 20 between the cap 18 and the plunger 16. The spring normally biases the sleeve and the plunger in a first position wherein the bores 56 in the plunger are not in register with the holes 38 in the sleeve. As the plunger is moved toward the interior of the sleeve against the force of the spring 20 to a second position, the holes 38 and the bore 56 become registered in alignment.
In U.S. Pat. No. 4,453,292 to John A. Bakker issued on Jun. 12, 1984, there is taught a cord lock which includes a cylinder 12, a plunger 14 and a helical compression biasing spring 16 trapped therebetween. A pair of teeth 58 formed on the plunger rides in lead-in ramps 30 disposed inwardly of the cylinder's open end when the piston is assembled into the cylinder by being moved axially towards the closed end of the cylinder. As a result, the teeth cam over the ramps and the shoulder 62 of the teeth will snap into respective pair of aligned lateral apertures 34 to retain the piston in assembled relation to the cylinder.
There is disclosed in U.S. Pat. No. 4,622,723 to Mark J. Krauss issued on Nov. 18, 1986, a cord lock which includes a housing 11 having a bottom wall 17 so as to form a recess 18 and opposed side walls 13, 14 with holes 21, 22 and an insert 12 slidably received in the recess. The insert includes a plunger portion 30 and an integral W-shaped spring portion 31 disposed on the end thereof. The plunger portion is formed with a throughhole 35. When the plunger is depressed and the spring is compressed, the plunger throughhole 35 aligns with the holes 21 and 22 on the housing sides so as to receive a cord.
In U.S. Pat. No. 4,675,948 to Sigurd W. Bengtsson issued on Jun. 30, 1987, there is taught a cord locking device which includes a sleeve 13 and a latching slide 14 insertable therein. The latching slide comprises a body 17 terminating outwardly in a head 18, and a spring 19 formed of a zig-zag material is made integral with the body 17. The sleeve 13 includes openings 12a and 12b formed on the long sides thereof, and an opening 12c is formed in the body 17 which is placeable in register with the openings in the sleeve.
The remaining patents listed above but not specifically discussed are believed to be of only general interest and show the state of the art in cord clamping devices for securely retaining a flexible cord or drawstring in a fixed position with respect to the clamping device.
However, none of the prior art uncovered in the search disclosed a cord closure like that of the present invention which includes means for initially holding the plunger sub-assembly in a pre-assembled position with a spring being compressed so that the throughhole of the plunger and the holes of a body housing can be readily aligned for insertion of a cord. This is accomplished by a retaining ring having a bottom surface and by providing prongs with lateral shoulders formed on a stem portion of the plunger which are lockingly engagable with the bottom surface of the retaining ring. As a result, the sub-assembly of the plunger, spring and retaining ring is then inserted telescopingly into the cavity of the body housing so as to coaxially align the throughhole of the plunger with the holes of the body housing for receiving the cord.